Microform word search method and apparatus

ABSTRACT

A digital imaging system and method for searching for expressions that appear on a microform medium, the system having a computer including a processor and an input device, and a digital microform imaging apparatus having an area sensor generating a digital microform image of the microform medium. The computer is configured to receive a search expression from the input device, create an expression template representing a shape of the search expression, and search the digital microform image for instances of the expression template.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and is a continuation applicationof U.S. patent application Ser. No. 14/874,971 filed on Oct. 5, 2015,which claims the benefit of and is a continuation application of U.S.patent application Ser. No. 12/832,487 filed on Jul. 8, 2010, now U.S.Pat. No. 9,158,983 the entire disclosures of which are considered partof the accompanying application and are hereby incorporated by referenceas if fully set forth herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a computer user interface for a digitalmicroform imaging apparatus and more specifically to a method andapparatus that facilitates word searching on real time microform imagesand that highlights instances of search words on a display when located.

Description of the Related Art

Microform images are useful in archiving a variety of documents orrecords by photographically reducing and recording the document in afilm format. Examples of typical microform image formats includemicrofilm/microfiche, aperture cards, jackets, 16 mm or 35 mm film rollfilm, cartridge film and other micro opaques. For example, a microfichearticle is a known form of graphic data presentation wherein a number ofpages or images are photographically reproduced on a single “card” ofmicrofiche film (such as a card of 3×5 inches to 4×6 inches, forexample). A large number of pages (up to a thousand or so) may bephotographically formed in an orthogonal array on a single microfichecard of photographic film. The microfiche film may then be placed in anoptical reader and moved over an optical projection path of a filmreader until a selected page is in the optical projection path. Thereader generates an image of the selected page which is then presentedon an imager screen for viewing. Although other electronic, magnetic oroptical imaging and storage techniques and media are available, thereexists an extensive legacy of film type records storing the likes ofnewspapers and other print media, business records, government records,genealogical records, and the like.

Early microform readers included a projection type system that projectedlight through the film and on to a screen as well as optics to adjustthe magnification of the images generated on the screen. To obtain acopy of an image, at least some of these systems were equipped withprinters that would print hard copies of any images required. Morerecently, digital microform imaging apparatus (DMIA) have been developedthat include an imaging sensor as well as optics for focusing filmimages onto the sensor. The sensor generates a digital bitmap image ofthe segment of the film in the optical projection path of the reader andprovides the bitmap image to a desktop computer. The computer uses thebitmap image to drive a display thereby generating a digital image ofthe film segment for viewing by a user. The computer can be used tomanipulate the bitmap image in many different ways including zooming inand out on the image, rotating the image, changing image contrast,annotating the image, etc. In addition, because the image is in adigital format, the image can be stored for subsequent access in anon-volatile memory.

The typical way microform systems are used is that a person that needsto locate information that may be stored on a microform mediumidentifies one or more microform storage medium (e.g., a microfilm roll)that may include the information being sought and loads the storagemedium onto a microform imaging machine. The user then attempts todetermine which section of the storage medium may include theinformation sought and aligns that segment of the storage medium withthe optical projection path to generate an image on a display. The userreads/examines the imaged segment or at least a portion thereof in anattempt to find the information sought. More often than not theinformation sought is not located in the imaged segment and thereforethe user moves on to a different segment of the storage medium or toanother storage medium without storing or printing out an image of thesegment. Once sought information is located in a segment, the user mayeither print out or store or both print and store the segment image forsubsequent access. Thus, in most cases, while a microform imager usermay examine a large number of microform segments, the user will onlystore or print a relatively small number of the segments for subsequentaccess.

In any medium in which most information is expressed in printed words,searching tasks are greatly expedited if word searching can beautomated. For instance, in the case of a 1000 page Microsoft Worddocument where one segment of the document discusses AlexanderHamilton's relationship with George Washington during the RevolutionaryWar, for a person unfamiliar with the layout of the document and in needof locating the segment discussing Hamilton, automated word searchcapability where a computer processor can locate each instance of thename “Alexander Hamilton” in the document is invaluable. In the case ofa Word document or the like, the stored document takes the form of a setof ASCII (American Standard Code for Information Interchange)characters, one for each character (i.e., letter, number, space, etc.)in the document. To search for a word, a processor simply compares anASCII character set representing the word with characters in thedocument and identifies instances of matches. Thereafter, the processormay highlight the space around each character in a matched word for auser to see via a computer output display screen.

In the case of a bitmap image like a PDF (Portable Document Format), oneway to search for words in the document is to perform an OpticalCharacter Recognition (OCR) process on the document prior to the wordsearch process to convert the PDF bitmap image into an ASCII typedocument (hereinafter “an OCR processed document”). After an OCRprocessed document has been generated and stored, a word search isperformed in the usual manner by comparing an ASCII character set thatrepresents a word to be searched with ASCII characters in the documentto locate instances of the word.

One other way to search for words in a PDF or other bitmap type documentis described in U.S. Pat. No. 5,687,253 (Hereinafter the '253 patent”).The '253 patent describes a word search process that is based on wordshapes as opposed to the results of a prior OCR process. To this end,the '253 patent describes that a bitmap document image can be processedto generate a word shape for each word in the document and then the wordshapes of known words from a dictionary can be compared to the wordshapes of the words in the document.

While several advantages are associated with word searching capabilitiesin images that include text, there is no known microform imaging systemthat facilitates word searching capabilities of any images, much lessreal time images generated by an imaging system.

BRIEF SUMMARY OF THE INVENTION

The present disclosure includes a microform imaging system that includesa processor that uses a digital bitmap image from a microform system todrive a display with a real time image and that enables a user to entera search expression/word, instances of which are to be located andvisually distinguished in the real time image. The visuallydistinguished words help the user to ascertain whether or not aparticular image is of interest to the user and, when an image is ofinterest, the user can either store the image in long term non-volatilememory or can print out a copy of the image. Thus, in at least somecases real time images are searched for words/expressions and there isno need to store the images in non-volatile memory prior to searching.

In at least some embodiments the processor performs the word searchfunction without the need to convert text in the image via OCR processesto character strings. This is accomplished in some embodiments bycreating a search template for a search expression and using thetemplate to search for word instances. Searching via a word searchtemplate as opposed to via an OCR processed document has been found tobe faster and in some cases more accurate. Some embodiments of thedisclosure include an apparatus for searching for expressions thatappear on a microform medium, the apparatus comprising a microformimager including a sensor for generating digital microform images of onesegment of the microform medium at a time, a display screen and aprocessor programmed to, while the microform imager is generating adigital microform image (i) use the digital microform image generated bythe microform imager to drive the display screen, (ii) search thedigital microform image presented via the display screen for instancesof a search expression and (iii) visually distinguish the located searchexpressions in the digital microform image presented via the displayscreen.

In some cases the segment of the microform imaged by the sensor can bechanged and wherein, when the segment of the microform imaged is changedfrom a first segment to a second segment so that a first digitalmicroform image corresponding to the first segment is replaced by asecond digital microform image corresponding to the second segment, theprocessor eliminating the first digital microform image from memory sothat the first digital microform image is not persistently stored forsubsequent access. In some embodiments the apparatus further includes apersistent non-volatile memory and an input device whereby a user canindicate via the input device that a displayed digital microform imageshould be stored in the persistent memory and wherein, prior to anindication that the digital microform image should be stored in thepersistent memory, the digital microform image is stored in anon-persistent memory.

In some cases the processor stores the digital microform image in randomaccess memory (RAM) as a RAM image and searches the RAM image forinstances of the search expression. In some embodiments the apparatusfurther includes a non-volatile memory in which at least a subset ofdigital microform images are to be persistently stored, the processorsearching for instances of the search expression in digital microformimages prior to storing the images in the non-volatile memory. In somecases the processor visually distinguishes by highlighting instances ofthe search expression in the digital microform image presented on thedisplay screen. In some embodiments the apparatus further includes aninput device useable to specify the search expression, the processorsearching by searching for the search expression entered via the inputdevice. In some cases the input device includes a search input fieldpresented via the display screen in which an apparatus user enters thesearch expression. In some cases the microfilm medium segment used togenerate the digital microfilm image can be changed by a user andwherein, when the microfilm medium segment used to generate the digitalimage is changed, the digital microform image presented via the displayis changed and the search input field is persistently presented via thedisplay screen so that the user can cause the processor to search forthe search expression in the changed digital microform image.

In some cases the search expression includes a word. In some cases theprocessor searches for search expression instances without performingOCR on the digital microform image. In some cases the processor searchesfor instances of the search expression by first creating an expressiontemplate representing the shape of the search expression and thensearching the digital microform image for instances of the expressiontemplate. In some cases the processor searches for instances of theexpression template by selecting a portion of the expression template asan initial template, searching the digital microform image for instancesof the initial template to identify expression candidates and thensearching areas around each expression candidate within the digitalmicroform image for an instance of the search expression using theexpression template.

Other embodiments include an apparatus for searching for expressionsthat appear on a microform medium, the apparatus comprising a microformimager including a sensor for generating a digital microform image ofone segment of the microform medium at a time wherein the imagerincludes controls for changing the segment of the microform medium thatis used to generate the digital image, a display screen for displayingthe digital microform image, a non-volatile memory and a processorprogrammed to receive the digital microform image generated by theimager and, prior to persistently storing the digital microform image inthe non-volatile memory (i) search for instances of a search expressionin the digital microform image and (ii) when at least one instance ofthe search expression is located within the digital microform image,visually distinguish the at least one instance of the search expressionon the display screen.

Some embodiments include a method for searching for expressions thatappear on a microform medium, the method comprising the steps of using amicroform imager including a sensor to generate digital microform imagesof one segment of the microform medium at a time, while the microformimager is generating a digital microform image (i) using the digitalmicroform image generated by the microform imager to drive a displayscreen, (ii) searching the digital microform image presented via thedisplay screen for instances of a search expression and (iii) visuallydistinguishing the located search expressions in the digital microformimage presented via the display screen.

In some cases the segment of the microform imaged by the sensor can bechanged and wherein, when the segment of the microform imaged is changedfrom a first segment to a second segment so that a first digitalmicroform image corresponding to the first segment is replaced by asecond digital microform image corresponding to the second segment,eliminating the first digital microform image from memory so that thefirst digital microform image is not persistently stored for subsequentaccess.

In some cases the method is for use with a persistent non-volatilememory and an input device, the method further including the steps ofreceiving an indication via the input device that a displayed digitalmicroform image should be stored in the persistent memory and wherein,prior to the indication that the digital microform image should bestored in the persistent memory, storing the digital microform image ina non-persistent memory. In some cases the method further includes thestep of storing the digital microform image in random access memory(RAM) as a RAM image and searching the RAM image for instances of thesearch expression. In some cases the method is for use with anon-volatile memory in which at least a subset of digital microformimages are to be persistently stored, the method further including thestep of searching for instances of the search expression in digitalmicroform images prior to storing the images in the non-volatile memory.In some cases the step of visually distinguishing includes highlightinginstances of the search expression in the digital microform imagepresented on the display screen.

In some cases the method is for use with an input device useable tospecify the search expression, the method including searching for searchexpression entered via the input device. In some cases the input deviceincludes a search input field presented via the display screen in whichan apparatus user enters the search expression. In some cases themicrofilm medium segment used to generate the digital microfilm imagecan be changed by a user and wherein, when the microfilm medium segmentused to generate the digital image is changed, the digital microformimage presented via the display is changed and the search input field ispersistently presented via the display screen so that the user can causesearching for the search expression in the changed digital microformimage. In some cases the search expression includes a word.

In some cases the step of searching for search expression instancesincludes searching without performing OCR on the digital microformimage. In some cases the step of searching for instances of the searchexpression includes first creating an expression template representingthe shape of the search expression and then searching the digitalmicroform image for instances of the expression template. In some casesthe step of searching for instances of the expression template includesselecting a portion of the expression template as an initial template,searching the digital microform image for instances of the initialtemplate to identify expression candidates and then searching areasaround each expression candidate within the digital microform image foran instance of the search expression using the expression template.

Yet other embodiments include a method for searching for expressionsthat appear on a microform medium, the method comprising the steps ofusing a sensor to generate a digital microform image of one segment ofthe microform medium at a time wherein the imager includes controls forchanging the segment of the microform medium that is used to generatethe digital image and using a processor to receive the digital microformimage generated by the imager and, prior to persistently storing thedigital microform image in a non-volatile memory (i) searching forinstances of a search expression in the digital microform image and (ii)when at least one instance of the search expression is located withinthe digital microform image, visually distinguish the at least oneinstance of the search expression on the display screen.

These and other objects, advantages and aspects of the invention willbecome apparent from the following description. In the description,reference is made to the accompanying drawings which form a part hereof,and in which there is shown a preferred embodiment of the invention.Such embodiment does not necessarily represent the full scope of theinvention and reference is made therefore, to the claims herein forinterpreting the scope of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view a DMIA and associated computer that areconsistent with at least some aspects of the present invention;

FIG. 2 is a schematic illustrating various components of the DMIA andcomputer shown in FIG. 1 in greater detail;

FIG. 3 is a perspective view of the DMIA shown in FIG. 1;

FIG. 4 is a schematic illustrating a screenshot of the user interfaceshown in FIG. 1;

FIG. 5 is a similar to FIG. 4, albeit showing a screenshot where adisplayed microform image shown in FIG. 4 has been enlarged;

FIG. 6 is a schematic illustrating a search template that is consistentwith at least some aspects of the present invention;

FIG. 7 is a schematic illustrating a portion of the template shown inFIG. 6 that is used during a first phase of a search process in at leastsome embodiments of the present invention;

FIG. 8 is a schematic illustrating a line search pattern over microformimage text that is consistent with at least some embodiments of thepresent invention;

FIG. 9 is a schematic illustrating exemplary match scores for a possibletemplate to search expression match that is consistent with at leastsome embodiments of the present invention;

FIG. 10 is a flow chart illustrating a search process that is consistentwith at least some aspects of the present invention; and

FIG. 11 is sub-process that may be substituted for a portion of theprocess shown in FIG. 10, to search for instances of a search expressionin an iterative fashion.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein like reference numerals correspondto similar elements throughout the several views and, more specificallyto FIG. 1, there is shown a digital microform imaging system 20 whichgenerally includes a digital microform imaging apparatus (DMIA) 22connected to a computer 24. Referring also to FIG. 2, computer 24includes one or more displays 26, one or more user input devices such asa keyboard 28 and/or a mouse 30, a processor 31, a temporary memory 33(i.e., a random access memory (RAM)) and a non-volatile memory 35. DMIA22 and computer 24 can be placed on a worksurface 32 of a desk or thelike for convenient access and ease of use. DMIA 22 is connected forcommunication (e.g. via Firewire IEEE 1394) to computer 24 via cable 34.Although cable 34 is described as an electrical type cable,alternatively DMIA 22 and computer 24 can communicate via fiber optics,wirelessly through infrared or radio frequencies, etc. Other details ofcomputer 24 and the general computing environment are discussed in moredetail below.

DMIA 22 is described in U.S. patent application Ser. No. 11/748,692,titled “DIGITAL MICROFORM IMAGING APPARATUS”, filed May 15, 2007, whichapplication is incorporated by reference. Referring more particularly toFIGS. 2 and 3, DMIA 22 includes an approximately monochromaticillumination source 36, such as a light emitting diode (LED) array whichtransmits incident light 38 through a diffuse window 40 along a firstoptical axis 42 of apparatus 22. Light emitting diode (LED) array 36 canbe an approximately 13×9 array of individual LEDs operating in the495-505 nm wavelength region, although array 36 is not limited to suchparameters. The relatively monochromatic nature of source 36 helpsreduce chromatic aberration in DMIA 22, thereby improving the opticalresolution of the images produced. Diffuse window 40 can be a frostedglass which diffuses the light emanating from array 36, thereby creatinga more uniform illumination source.

A microform media support 44 is configured to support a microform media46 within the path of light 38 and along first optical axis 42. In theembodiment shown support 44 is an X-Y table which is movable in a planewhich is approximately orthogonal to first optical axis 42. Microformmedia support 44 includes a frame which supports a first window 50 onone side of media 46 and a second window 52 on the other side of media46. Although not shown, second window 52 hinges upward when the frame ismoved forward and similarly hinges downward when the frame is movedrearward. In this way the microform media 46 can be placed and heldsecurely between windows 50, 52 for viewing.

An approximately 45° fold mirror 70 (FIG. 2) reflects the incident lighttransmitted through microform media 46 approximately 90° along a secondoptical axis 72. First optical axis 42 and second optical axis 72 can bethought of as segments of the single or main optical axis. Fold mirror70 advantageously shortens the overall longitudinal length of theoptical axis which allows DMIA 22 to be more compact.

An imaging subsystem includes a lens 90 that includes an adjustableaperture. Lens 90 may have a fixed focal length of 50 mm, for example,which has the advantage of a relatively large depth of focus. An areasensor 92 includes an area array CCD sensor with a two dimensional arrayof sensor elements or pixels, for example, with a 3.5 μm2 pixel size, orother types of sensors and pixel sizes depending on resolution sizerequirements. The area array nature of sensor 92, when compared to aline sensor, eliminates the need for scanning of the sensor when viewingtwo dimensional images. A light baffle 126 can be connected to areasensor 92 to reduce stray light incident on sensor 97 and therebyfurther improve the resolution and signal to noise of DMIA 22. Lightbaffle 126 can have an antireflective coating at the front and insidesurfaces of the baffle to further reduce stray light incident on sensor92. Algorithms for moving the lens and sensor to appropriate respectivelocations to achieve proper magnification and focus of an image allowsDMIA 22 to autofocus without the need for iterative measurements andrefocusing of the lens 90 during magnification changes to accommodatedifferent reduction ratios of different film media.

A controller 116 is electrically connected to motors associated withlens 90 and area sensor 92 where the controller 116 is for receivingcommands and other inputs from computer 24 or other input devices,controlling the motors and other elements of DMIA 22, and for outputtinga digital microform image corresponding to area sensor 92. To this end,controller 116 includes one or more circuit boards which have amicroprocessor, field programmable gate array, application specificintegrated circuit or other programmable devices; motor controls; areceiver; a transmitter; connectors; wire interconnections includingribbon wire and wiring harnesses; a power supply; and other electricalcomponents. Controller 116 also provides electrical energy and lightingcontrols for LED array 36. The motors can be DC servomotors, or othermotors.

The present invention is not limited by the DMIA 22 shown as there areother DMIAs, or microfilm or micro opaque readers, scanners, etc., whichare available which can be used in conjunction with a computer and theCUI of the present invention. Further, the present invention is notlimited by a separate DMIA 22 and computer 24. For example, computer 24can be integrated into DMIA 22, or can be part of controller 116. Yetfurther, monitor 26 can be a part of DMIA 22 instead of a separatedevice.

Media 46 can include any microform image formats such asmicrofilm/microfiche, aperture cards, jackets, 16 mm or 35 mm film rollfilm, cartridge film and other micro opaques. Micro opaques aredifferent than transparent film. Images are recorded on an opaquemedium. To view these micro images one needs to use reflected light. Thepresent invention can use LED arrays (not shown) for use with microopaques, which can be the same, or similar to, the monochromatic LED'sthat are used in illumination source 36. In the embodiment of FIG. 3,DMIA 22 includes a microform media support in the form of motorized rollfilm attachment with supply side 62 and take up side 64 and film guides66 and 68, in addition to an X-Y table 44.

Referring now to FIGS. 1 and 4, computer 24 includes a software computeruser interface (CUI) 100 displayed by monitor 26 with user inputs tocontrol DMIA 22 in general. CUI 100 can be in the form of at least oneinstruction executed by processor 31, where the instructions of 100 arestored on a computer-readable storage medium. CUI 100 generally includesa display area 104 and a toolbar 102 with user selectable controls. Theuser selectable controls presented via toolbar 159 include, amongothers, an image zoom control repeated by icon 114, a save controlrepresented by icon 112 and a word search control represented by searchicon 120. The toolbar controls 159 can be selected by a user moving amouse controlled cursor 122 (see FIG. 4) on to one of the icons and aleft clicking mouse 30. A film control tool 110 is also presented viaCUI 100 that can be used by a system user to advance or back up a rollof film supported by DMIA 22.

Referring still to FIG. 4, and also again to FIGS. 1 through 3, when aDMIA user places a microform segment within the path of light 38, sensor92 generates a digital microform image which is provided via cable 34 toprocessor 31. Processor 31 uses the digital microform image to directlydrive display 26. Thus, as the microform image is altered, the imagepresented via display 26 is immediately altered as well so that theimage obtained by sensor 92 is always used to drive display 26essentially in real time. Here, the bitmap image that is displayed isnot stored in non-volatile memory 35 until the system user selects saveicon 112. By not storing the real time images, the process of scanningthe microform segments and presenting the segments via display 26 isexpedited and the overall process is more appealing to the end user asscanning and image presentation appears to be and actually is morefluid.

In FIG. 4, an exemplary image of a front page of a newspaper is shown indisplay area 104. The image includes pictures and text which comprisevarious articles. The icons in toolbar area 102 can be selected tomodify the appearance of the microform image area 104. For example, asegment or portion of the image in area 104 is shown in an enlarged orzoomed format in FIG. 5. Here, the image in area 104 is a digital bitmap image and, in at least some embodiments, the image is neverprocessed via an optical character recognition (OCR) process.

Referring still to FIGS. 4 and 5, one particularly advantageous functionthat is associated with the present disclosure allows a system user tocause processor 31 (see also FIG. 2) to search an image presented withinarea 104 for specific words or phrases that may be of interest to thesystem user. For example, where a system user is looking for articlesrelated to a House of Representatives within a state, the user may wantto search for any instances of the term “House” in stories within anewspaper that is stored on a microform storage medium. With an image tobe searched presented in area 104, referring to FIG. 4, a system usercan select search icon 120 via cursor 122. When icon 120 is selected, inat least some embodiments of the present disclosure, a separate “findtext” window 108 is opened. Window 108 includes a title bar 130, a“window close” icon 132, a search expression field 134, and a “find”icon 136. Title bar 130 can be used to move window 108 to differentlocations within CUI 100. Window close icon 132 can be selected to closethe find text window 108. Expression field 134 is provided to allow theuser to enter text or a phrase to be searched for within the presentedimage. Here, text is entered by selecting field 134 and then usingkeyboard 28 (see again FIG. 1). Once a search expression is enteredwithin field 134, the user can select find icon 136 to submit the searchexpression to processor 31 for searching purposes.

Referring still to FIG. 4 and now also to FIG. 5 where a portion of theimage in FIG. 4 has been enlarged, it can be seen that in the presentexample, after the term “house” has been entered in field 134 and findicon 136 has been selected, the processor 31 locates four separateinstances of the search expression “house,” where the separate instancesare labeled 150 a, 150 b, 150 c and 150 d. In the illustratedembodiment, each instance of the search expression identified within apresented image is visually distinguished in some fashion. For instancein FIGS. 4 and 5, each instance 150 a through 150 d is visuallydistinguished by placing a rectangle around the instance. Other ways ofvisually distinguishing include highlighting each instance, placing ablinking box around each instance, placing an arrow adjacent eachinstance, etc.

Importantly, the expression or work search method in at least someembodiments of the present invention is preformed without the need forOCR processing and instead is performed directly on the bit map imagepresented within area 104. To this end, in at least some embodiments,after a search expression has been received by processor 31, theprocessor creates a template of the search word or expression and thenperforms an iterative search of the displayed image to find instances ofthe expression. More specifically, in at least some embodiments,referring to FIG. 6, to create a search expression template, after asearch expression has been received, processor 31 lays a multi-columnand row raster over the search expression and then, for each element inthe raster, generates an element value that indicates a percentage ofthe element covered by the search expression. In FIG. 6, raster elementsare generally identified by numeral 182 where an “H” from the searchexpression “house” is shown covering a portion of the raster whereraster elements that are overlapped by the search expression are shownin cross-hatch. Exemplary elements overlapped by the letter H arecollectively identified by numeral 186. The combination of numbersrepresenting the percentages of elements overlapped by the searchexpression comprise the template 180 in the present example. Othertemplate types are contemplated where weights may be applied to elementvalues based on empirical data related to modifications that tend toincrease accuracy of search results. In addition, more complex templatesare contemplated, the illustrated template having been simplified in theinterest of simplifying this explanation.

After the search expression template has been generated, in at leastsome embodiments, processor 31 selects a portion of the template to beused during a first rough phase of the image searching process designedto quickly identify word/expression match candidates. Referring to FIG.7, in at least some embodiments, the template portion used for the firstphase of the search includes a generally central line pattern 190through the template elements where each element in the selected portionincludes a number indicating the percentage of the element overlapped bythe search expression. Hereinafter, the portion 190 is described as acenter pattern. While a center pattern is used in the present exampleduring the first phase of searching, it should be appreciated that otherpatterns derived from the template may be employed and the inventionshould not be limited to use of a center pattern during the first roughsearch phase.

After the center pattern 190 has been identified, referring to FIG. 8,the processor 31 searches along a series of horizontal lines through theimage presented in area 104 (see again FIG. 5) for possible matchesbetween the center pattern and data within the digital bit map microformimage. Exemplary search lines are collectively labeled 200 in FIG. 8.While only a small number of search lines are shown in FIG. 8, it shouldbe appreciated that a large number of search lines are used duringnormal operation so that any and all instances of the center pattern aredetected and associated with at least one of the search lines. An exactmatch between the center pattern and a portion of a search line is notrequired to identify a possible instance of the search expression andinstead, some error is tolerated as a second search phase is used toeliminate erroneous instances of identified search expressions. In FIG.8, exemplary lines 200 a, 200 b, 200 c, and 200 d correspond to separatepossible instances of the search expression house.

Once possible instances of the search expression have been located,processor 91 uses the entire search template 180 to search the areaaround each possible instance to more accurately identify and verifyinstances of the search expression that have been identified. To thisend, referring to FIG. 9, for each element 222 in the search template,in at least some embodiments, match scores are provided that indicatehow closely a possible search expression instance matches the template.In FIG. 9, match scores are provided for each template element (seecross-hatched elements) that is at least partially overlapped by thesearch expression (see “H” and portion of “O” in FIG. 9) where arelatively higher match score indicates a better correlation between atemplate element and a match candidate element. Where the combination ofmatched scores corresponds to a value that is greater that a matchthreshold, a template to expression match is determined to have occurredand processor 31 then highlights or otherwise visually distinguishes theinstance within area 104 (see again FIG. 5).

Referring now to FIG. 10, an exemplary method 158 that is consistentwith at least some aspects of the present invention is illustrated.Referring also to FIGS. 1 and 2, at process block 160, a user places amicroform segment in the viewing area of DMIA 22 and at block 92, sensor116 generates a digital bit map microform image which is provided toprocessor 31. At block 164, processor 31 uses the microform image todrive display 26 in real time.

Referring still to FIGS. 1, 2 and 10, at decision block 166, processor31 determines whether or not a system user has indicated that thepresented image should be stored in the non-volatile memory 35. Wherethe user indicates that the image should be stored in non-volatilememory 35, control passes to block 168 where the image is stored forsubsequent access. At block 166, if the user does not indicate that theimage should be stored, control passes to block 170 where processor 31determines whether or not the user has indicated a desire to search fora word or phase within the image presented. If the user has notindicated a desire to search, control passes back up to block 162 wherethe microform segment continues to be imaged.

Once again, referring to FIG. 4, a user indicates a desire to search byselecting icon 120. Once icon 120 is selected, control passes to block172 where processor 31 presents the find text window 108 shown in FIG.4. At block 174, a user enters a search expression or word to besearched in field 134 and then selects find icon 136.

Referring still to FIGS. 1, 2 and 10, after find icon 136 is selected(see again FIG. 4), processor 31 searches the displayed bit map image inreal time for the search expression (i.e., for the entered word). Atdecision block 178, where one or more instances of the word are located,control passes to block 182 where processor 31 highlights the instanceor multiple instances of the word/search expression in the bit mapimage. Where an instance of the search expression has been identified atblock 178, control passes to block 180 where processor 31 indicates thatno match has occurred in some fashion. After blocks 180 and 182, controlpasses back up to block 162 where the process continues as above. If auser switches the segment of the microform storage medium that is beingimaged via DMIA 22, process 158 is repeated for the new segment. In atleast some embodiments, when a user performs a word search of onesegment and then switches to view another microform segment, the findtext box 108 (see again FIG. 4) remains on the CUI with the previouslysought search expression in field 134 so that the user can simplyreselect find icon 136 to continue the search process using the samesearch expression.

Referring now to FIG. 11, a sub-process 240 that maybe substituted for aportion of the process shown in FIG. 10 is illustrated. Referring alsoto FIG. 10, after a search word or expression has been received byprocessor 31 at block 174, control may pass to block 242 in FIG. 11where processor 31 creates a template as shown best in FIG. 6. Next, atblock 244, processor 31 uses the center pattern 190 (see again FIG. 7)from the template to line search (see again FIG. 8) throughout thedisplayed microform image for possible instances of the searchexpression. At decision block 246, where no potential matches haveoccurred, control passes to block 248. At decision block 248, where theentire displayed image has been examined, control passes back to block180 in FIG. 10 where processor 31 indicates that no match has occurred.At block 248, where the entire displayed image has not been examined,control passes back up to block 244 where processor 31 continues theline searching process.

Referring still to FIG. 11, at decision block 246, where a potentialmatch has been identified, control passes to block 252 where processor31 compares the entire search template to an area proximate thepotential match. At block 254, where a search expression match has beenverified, control passes back to block 182 in FIG. 10 where the instanceor instances of the search expression in the bit map are highlighted.

The foregoing description was primarily directed to a preferredembodiment of the invention. Although some attention was given tovarious alternatives within the scope of the invention, it isanticipated that one skilled in the art will likely realize additionalalternatives that are now apparent from disclosure of embodiments of theinvention. Accordingly, the scope of the invention should be determinedfrom the following claims and not limited by the above disclosure.

To apprise the public of the scope of this invention, the followingclaims are made:

What is claimed is:
 1. A digital imaging system for searching forexpressions that appear on a microform medium, the system comprising: acomputer including a processor, a display, a memory, and an inputdevice, wherein the processor is in communication with the display, thememory, and the input device; and a digital microform imaging apparatusincluding a controller and an area sensor generating a digital microformimage of the microform medium, the controller is in communication withthe area sensor and receives the digital microform image from the areasensor, and the controller is in communication with the processor andoutputs the digital microform image to the processor; wherein theprocessor is configured to receive a search expression from the inputdevice, create an expression template representing a shape of the searchexpression by laying a multi-column row raster over the searchexpression and generating an element value for each element in theraster that indicates a percentage of the element covered by the searchexpression, and search the digital microform image for instances of theexpression template.
 2. The digital imaging system of claim 1, whereinthe computer is integrated into the digital microform imaging apparatus.3. The digital imaging system of claim 1, wherein the processor isconfigured to visually distinguish identified instances of the searchexpression on the display.
 4. The digital imaging system of claim 1,wherein the area sensor is configured to generate the digital microformimage that is a segment of the microform medium.
 5. The digital imagingsystem of claim 1, wherein the processor is configured to select aportion of the expression template to identify expression candidates andsearch the digital microform image at areas around the expressioncandidates for an instance of the search expression using the expressiontemplate.
 6. The digital imaging system of claim 1, wherein thecontroller is in communication with the processor via a cable.
 7. Thedigital imaging system of claim 1, wherein the area sensor is configuredto generate the digital microform image that is a bitmap image.
 8. Thedigital imaging system of claim 1, wherein the input device is at leastone of a keyboard and a mouse.
 9. The digital imaging system of claim 1,wherein the processor and the controller are integrated.
 10. A method ofsearching for expressions that appear on a microform medium using adigital imaging system, the system comprising a computer including aprocessor, a display, a memory, and an input device, and a digitalmicroform imaging apparatus including an area sensor, the methodcomprising the steps of: generating with the area sensor a digitalmicroform image of the microform medium; communicating the digitalmicroform image to the computer; communicating a search expression fromthe input device to the computer; creating with the computer anexpression template representing a shape of the search expression; andsearching with the computer the digital microform image for theexpression template; wherein the step of creating with the computer theexpression template representing the shape of the search expressioncomprises: laying with the computer a multi-column row raster over thesearch expression; and generating with the computer an element value foreach element in the raster that indicates a percentage of the elementcovered by the search expression.
 11. The method of claim 10 wherein thestep of creating with the computer the expression template representingthe shape of the search expression comprises selecting with the computera portion of the expression template to be used during a first roughphase, the portion including element values along the portion.
 12. Themethod of claim 11 wherein the step of selecting with the computer theportion of the expression template to be used during a first rough phasecomprises selecting the portion along a central line pattern through theelements.
 13. The method of claim 10 wherein the step of searching withthe computer the digital microform image for the expression templatecomprises searching along a series of horizontal lines through thedigital microform image for possible matches.
 14. The method of claim 13wherein the step of searching with the computer the digital microformimage for the expression template comprises the computer using theexpression template to search areas around each possible match.
 15. Themethod of claim 14 wherein the step of searching with the computer thedigital microform image for the expression template comprises generatingwith the computer a match score indicating how closely each possiblematch matches the expression template.
 16. The method of claim 15wherein the step of searching with the computer the digital microformimage for the expression template comprises visually distinguishing eachpossible match when the match score for the possible match exceeds amatch threshold.
 17. A method of searching for expressions that appearon a microform medium using a digital imaging system, the systemcomprising a computer including a processor, a display, a memory, and aninput device, and a digital microform imaging apparatus including anarea sensor, the method comprising the steps of: the area sensorgenerating a digital microform image of the microform medium; thecomputer receiving the digital microform image; the computer receiving asearch expression from the input device; the computer creating anexpression template representing a shape of the search expression; thecomputer laying a multi-column row raster over the search expression;the computer generating an element value for each element in the rasterthat indicates a percentage of the element covered by the searchexpression; the computer searching the digital microform image for theexpression template.
 18. The method of claim 17 further comprising thesteps of: the computer selecting a portion of the expression template asan initial template; the computer searching the digital microform imagefor instances of the initial template to identify expression candidates;the computer searching areas around each expression candidate within thedigital microform image for an instance of the search expression usingthe expression template.
 19. The method of claim 18 further comprisingthe step of the computer comparing the entire expression template to theareas around each expression candidate.
 20. The method of claim 10,wherein the step of generating with the area sensor a digital microformimage of the microform medium comprises generating with the area sensora bitmap image.
 21. The method of claim 11, wherein step of searchingwith the computer the digital microform image for the expressiontemplate comprises searching with the computer the digital microformimage for instances of the portion of the expression template toidentify possible matches.
 22. The method of claim 21 wherein step ofsearching with the computer the digital microform image for theexpression template further comprises the computer using the entireexpression template to search areas around each possible match.